Production of polymers of ketene and preparation of esters thereof



Patented Dee-28,1937

PRODUCTION OF POL RS 015 KETENE AND PREPARATION OF ESTER-S THERE- Peter.l. Wiezevicli and Anthony H. Gleason,

Elizabeth, N. 3., 'assignors to Standard Oil Development Company, acorporation of Delaware No Drawing. Application April1'7,1934,

Serial No. ironic 7 Claims. I (Cl. 260-lili) This application is acontinuation in part of the pending application Serial no. 559,936 nowPatent 1,998,404 of Peter J. Wiezevich and Anthony H. Gleason, filedAugust 28, 1931, for

the production of polymers of ketene and preparation of esters thereof.

The invention herein claimed relates to the utilization ofpolymerization'products of ketenes. More particularly, it relates to theemployment of the dimer ofketene, cyclobutane 1:3 dione, in

the manufacture of commercially valuable products. a

In our original application, Serial No. 559,936 filed on August 28,1931, a method has been described for the preparation in high yields ofcyclobutane 1:3 dione, presumably having the formula =C-CH2 by thepolymerization of ketene (CI-12:00).

This is accomplished by subjecting'ketene to pressures higher thanatmospheric such as 2 to- 200 atmospheres and .under suitableconditions. It has been found preferable to allow the compressed keteneto stand in contact with a metallic surface at moderately lowtemperatures. As an example, ketene formed by the pyrolysis of acetone,was separated from acetone by cooling with solid carbon dioxide-alcoholmixture, liquefied by cooling with liquid air, introduced into a steelbomb and allowed to warm up to room temperature under its own pressure.After standing approximately 8 to 12 hours, the products of the bombcontained cyclobutane 1:3 dione correspending to a yield of- 85% of thetheoretitical yield. Other metals such as copper, chrome nickel steel,eta, may be employed. ,The ketene,

instead of being liquefied by-cooling, as in the example given, may becompressed into the metal container by a compressor or the like atatemperature of about 0 C. to 100 C.

The cyclobu tane 1:3 dione (boiling point being about 127 C.) soprepared, may be considered as the anhydride of aceto-acetic acid sinceit reacts with water to give aceto-acetic acid. The presentinventiondeals with treating this dimer as well as any other polymerizationproducts of ketene under suitable conditions causing it to react withvarious other compounds. As an example, cyclic and/or aliphatic hydroxycompounds wer. heated at moderate temperatures .such as approximately 25C.'to less than 127 C.

' with cyclobutane 1:3 dione, preferably in the presence of smallamounts of catalysts, for example mineral acids such as hydrochloricacid, etc. or metallic salts such as sodium bisulfate,

' .etc., to give esters known as aceto-acetates. If

the reaction is performed under pressures greater than atmospheric,temperatures higher than 127 C. may be employed. A yield of to percentof aceto-acetic ester of ethyl alcohol was obtained in this manner.Similarly, aceto-acetic esters of other aliphatic alcohols, includingthe diand tri-hydric alcohols, may be prepared. Phenyl aceto-acetate hasalso been prepared in a similar manner from phenol with satisfactoryyield.

Other phenolic or aromatic hydroxy compounds,

Example 1 When cyclobutane 1:3 dione is treated with an excess ofalcohol and a trace of sulfuric acid, only traces of the ester could befound, and at the end of 10 days the odorof the dimer from the reactionmixture was still pronounced.

*Another sample'of the dione (37 g.) obtained by polymerizing ketene ina metal container under pressure was heated on a steam bath C.) with 40g. of absolute ethyl alcohol and 0.3 g. of sulfuric acid for 3 hours. Inspite of the thermal instability of the polymer, a yield of 80-85% ofethyl aceto-acetate, boiling at 68 C. at 10 mm. pressure was obtained bywashing the reaction product with saturated salt solution,

drying, filtering, and distilling under vacuum.

Example 2 About 15 cc. of phenol in ether solutionwas treated with 15cc. of the products (obtained by polymerization of ketene under pressurein a steel container), and a trace of sulfuric acid was added. Thereaction was so violent as to cause the mixture to boil over.Distillation of the red liquid gave-l5-20 cc. of a product boiling at139 C. at 7.mm. The phenyl aceto-acetate so obtained could be employedas a plasticizer.

Example 3 Some cotton was activated and then treated with a chloroformsolution of cyclobutane 1:3 dione. The fibersbegan to turn yellowimmediately and in a few minutes the mixture had a deep redcolor andsoon became thick and pasty and the resulting cellulose aceto-acetatewas separated and allowed to dry in the form of a thin tough film.

The foregoing description is merely illustrative and various changes andalternative arrangements may be made within the scope of theappendedclaims in which it is our intention to claim all noveltyinherent in the invention as broadly as the prior art permits.

We claim:

1. Method of preparing esters comprising reacting aliphatic poly-hydroxyalcohols with the products obtained by the polymerization of ketene inpresence of an acid e'sterification catalyst.

2. Method of preparing aceto-acetic esters comprising contactingcyclobutane 1:3 dione with an aliphatic poly-hydroxy alcohol in presenceof an acid esterification catalyst.

3. Method according to claim 2 in' which the hydroxy compound is analiphatic alcohol of the group consisting of diand triehydric alcohols.

4. Method according to claim 2 in which a temperature belowapproximately 127 C. is used.

5; Method according to claim 2 in which the contacting is done in thepresence of an inert solvent.

6. Method of preparing cellulose aceto-acetate which comprisescontacting cyclobutane 1:3 dione with cellulose material in presence ofan acid estcrification catalyst.

7. Cellulose aceto acetate.

PETER J. WIEZEVICH. ANTHONY H. GLEASON.

